CHỌN PHƯƠNG ÁN ĐÚNG (A, B, C HOẶC D) ĐỂ HÒAN THÀNH CÂU.PAY THE BILL W...

36. Choose A, B, C or D to complete the following sentence :

Our streets will be clean if .

A. people stop to litter B. people don’t stop to litter

C. people stop littering D. people don’t stop littering